2 * Copyright (C) 2008 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 #ifndef _DALVIK_THREAD
20 #define _DALVIK_THREAD
24 #if defined(CHECK_MUTEX) && !defined(__USE_UNIX98)
25 /* Linux lacks this unless you #define __USE_UNIX98 */
26 int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);
27 enum { PTHREAD_MUTEX_ERRORCHECK = PTHREAD_MUTEX_ERRORCHECK_NP };
30 #ifdef WITH_MONITOR_TRACKING
31 struct LockedObjectData;
35 * Current status; these map to JDWP constants, so don't rearrange them.
36 * (If you do alter this, update the strings in dvmDumpThread and the
37 * conversion table in VMThread.java.)
39 * Note that "suspended" is orthogonal to these values (so says JDWP).
41 typedef enum ThreadStatus {
42 /* these match up with JDWP values */
43 THREAD_ZOMBIE = 0, /* TERMINATED */
44 THREAD_RUNNING = 1, /* RUNNABLE or running now */
45 THREAD_TIMED_WAIT = 2, /* TIMED_WAITING in Object.wait() */
46 THREAD_MONITOR = 3, /* BLOCKED on a monitor */
47 THREAD_WAIT = 4, /* WAITING in Object.wait() */
49 THREAD_INITIALIZING = 5, /* allocated, not yet running */
50 THREAD_STARTING = 6, /* started, not yet on thread list */
51 THREAD_NATIVE = 7, /* off in a JNI native method */
52 THREAD_VMWAIT = 8, /* waiting on a VM resource */
55 /* thread priorities, from java.lang.Thread */
57 THREAD_MIN_PRIORITY = 1,
58 THREAD_NORM_PRIORITY = 5,
59 THREAD_MAX_PRIORITY = 10,
64 bool dvmThreadStartup(void);
65 bool dvmThreadObjStartup(void);
66 void dvmThreadShutdown(void);
67 void dvmSlayDaemons(void);
70 #define kJniLocalRefMax 512 /* arbitrary; should be plenty */
71 #define kInternalRefDefault 32 /* equally arbitrary */
72 #define kInternalRefMax 4096 /* mainly a sanity check */
74 #define kMinStackSize (512 + STACK_OVERFLOW_RESERVE)
75 #define kDefaultStackSize (12*1024) /* three 4K pages */
76 #define kMaxStackSize (256*1024 + STACK_OVERFLOW_RESERVE)
79 * Our per-thread data.
81 * These are allocated on the system heap.
83 typedef struct Thread {
84 /* small unique integer; useful for "thin" locks and debug messages */
88 * Thread's current status. Can only be changed by the thread itself
89 * (i.e. don't mess with this from other threads).
94 * This is the number of times the thread has been suspended. When the
95 * count drops to zero, the thread resumes.
97 * "dbgSuspendCount" is the portion of the suspend count that the
98 * debugger is responsible for. This has to be tracked separately so
99 * that we can recover correctly if the debugger abruptly disconnects
100 * (suspendCount -= dbgSuspendCount). The debugger should not be able
101 * to resume GC-suspended threads, because we ignore the debugger while
102 * a GC is in progress.
104 * Both of these are guarded by gDvm.threadSuspendCountLock.
106 * (We could store both of these in the same 32-bit, using 16-bit
107 * halves, to make atomic ops possible. In practice, you only need
108 * to read suspendCount, and we need to hold a mutex when making
109 * changes, so there's no need to merge them. Note the non-debug
110 * component will rarely be other than 1 or 0 -- not sure it's even
111 * possible with the way mutexes are currently used.)
117 * Set to true when the thread suspends itself, false when it wakes up.
118 * This is only expected to be set when status==THREAD_RUNNING.
122 /* thread handle, as reported by pthread_self() */
125 /* thread ID, only useful under Linux */
128 /* start (high addr) of interp stack (subtract size to get malloc addr) */
129 u1* interpStackStart;
131 /* current limit of stack; flexes for StackOverflowError */
132 const u1* interpStackEnd;
134 /* interpreter stack size; our stacks are fixed-length */
136 bool stackOverflowed;
138 /* FP of bottom-most (currently executing) stack frame on interp stack */
141 /* current exception, or NULL if nothing pending */
144 /* the java/lang/Thread that we are associated with */
147 /* the JNIEnv pointer associated with this thread */
150 /* internal reference tracking */
151 ReferenceTable internalLocalRefTable;
153 /* JNI local reference tracking */
154 ReferenceTable jniLocalRefTable;
156 /* JNI native monitor reference tracking (initialized on first use) */
157 ReferenceTable jniMonitorRefTable;
159 /* hack to make JNI_OnLoad work right */
160 Object* classLoaderOverride;
162 /* pointer to the monitor lock we're currently waiting on */
163 /* (do not set or clear unless the Monitor itself is held) */
164 /* TODO: consider changing this to Object* for better JDWP interaction */
165 Monitor* waitMonitor;
166 /* set when we confirm that the thread must be interrupted from a wait */
167 bool interruptingWait;
168 /* thread "interrupted" status; stays raised until queried or thrown */
172 * Set to true when the thread is in the process of throwing an
177 /* links to rest of thread list; grab global lock before traversing */
181 /* JDWP invoke-during-breakpoint support */
182 DebugInvokeReq invokeReq;
184 #ifdef WITH_MONITOR_TRACKING
185 /* objects locked by this thread; most recent is at head of list */
186 struct LockedObjectData* pLockedObjects;
189 #ifdef WITH_ALLOC_LIMITS
190 /* allocation limit, for Debug.setAllocationLimit() regression testing */
195 /* base time for per-thread CPU timing */
196 bool cpuClockBaseSet;
199 /* memory allocation profiling state */
200 AllocProfState allocProf;
203 #ifdef WITH_JNI_STACK_CHECK
207 #if WITH_EXTRA_GC_CHECKS > 1
208 /* PC, saved on every instruction; redundant with StackSaveArea */
209 const u2* currentPc2;
213 /* start point for an internal thread; mimics pthread args */
214 typedef void* (*InternalThreadStart)(void* arg);
216 /* args for internal thread creation */
217 typedef struct InternalStartArgs {
219 InternalThreadStart func;
225 volatile Thread** pThread;
226 volatile int* pCreateStatus;
230 bool dvmPrepMainForJni(JNIEnv* pEnv);
231 bool dvmPrepMainThread(void);
233 /* utility function to get the tid */
234 pid_t dvmGetSysThreadId(void);
237 * Get our Thread* from TLS.
239 * Returns NULL if this isn't a thread that the VM is aware of.
241 Thread* dvmThreadSelf(void);
243 /* grab the thread list global lock */
244 void dvmLockThreadList(Thread* self);
245 /* release the thread list global lock */
246 void dvmUnlockThreadList(void);
249 * Thread suspend/resume, used by the GC and debugger.
251 typedef enum SuspendCause {
255 SUSPEND_FOR_DEBUG_EVENT,
256 SUSPEND_FOR_STACK_DUMP,
258 #if defined(WITH_JIT)
262 void dvmSuspendThread(Thread* thread);
263 void dvmSuspendSelf(bool jdwpActivity);
264 void dvmResumeThread(Thread* thread);
265 void dvmSuspendAllThreads(SuspendCause why);
266 void dvmResumeAllThreads(SuspendCause why);
267 void dvmUndoDebuggerSuspensions(void);
270 * Check suspend state. Grab threadListLock before calling.
272 bool dvmIsSuspended(Thread* thread);
275 * Wait until a thread has suspended. (Used by debugger support.)
277 void dvmWaitForSuspend(Thread* thread);
280 * Check to see if we should be suspended now. If so, suspend ourselves
281 * by sleeping on a condition variable.
283 * If "self" is NULL, this will use dvmThreadSelf().
285 bool dvmCheckSuspendPending(Thread* self);
288 * Fast test for use in the interpreter. Returns "true" if our suspend
291 INLINE bool dvmCheckSuspendQuick(Thread* self) {
292 return (self->suspendCount != 0);
296 * Used when changing thread state. Threads may only change their own.
297 * The "self" argument, which may be NULL, is accepted as an optimization.
299 * If you're calling this before waiting on a resource (e.g. THREAD_WAIT
300 * or THREAD_MONITOR), do so in the same function as the wait -- this records
301 * the current stack depth for the GC.
303 * If you're changing to THREAD_RUNNING, this will check for suspension.
305 * Returns the old status.
307 ThreadStatus dvmChangeStatus(Thread* self, ThreadStatus newStatus);
310 * Initialize a mutex.
312 INLINE void dvmInitMutex(pthread_mutex_t* pMutex)
315 pthread_mutexattr_t attr;
318 pthread_mutexattr_init(&attr);
319 cc = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK_NP);
321 pthread_mutex_init(pMutex, &attr);
322 pthread_mutexattr_destroy(&attr);
324 pthread_mutex_init(pMutex, NULL); // default=PTHREAD_MUTEX_FAST_NP
329 * Grab a plain mutex.
331 INLINE void dvmLockMutex(pthread_mutex_t* pMutex)
333 int cc = pthread_mutex_lock(pMutex);
338 * Unlock pthread mutex.
340 INLINE void dvmUnlockMutex(pthread_mutex_t* pMutex)
342 int cc = pthread_mutex_unlock(pMutex);
349 INLINE void dvmDestroyMutex(pthread_mutex_t* pMutex)
351 int cc = pthread_mutex_destroy(pMutex);
356 * Create a thread as a result of java.lang.Thread.start().
358 bool dvmCreateInterpThread(Object* threadObj, int reqStackSize);
361 * Create a thread internal to the VM. It's visible to interpreted code,
362 * but found in the "system" thread group rather than "main".
364 bool dvmCreateInternalThread(pthread_t* pHandle, const char* name,
365 InternalThreadStart func, void* funcArg);
368 * Attach or detach the current thread from the VM.
370 bool dvmAttachCurrentThread(const JavaVMAttachArgs* pArgs, bool isDaemon);
371 void dvmDetachCurrentThread(void);
374 * Get the "main" or "system" thread group.
376 Object* dvmGetMainThreadGroup(void);
377 Object* dvmGetSystemThreadGroup(void);
380 * Given a java/lang/VMThread object, return our Thread.
382 Thread* dvmGetThreadFromThreadObject(Object* vmThreadObj);
385 * Sleep in a thread. Returns when the sleep timer returns or the thread
388 void dvmThreadSleep(u8 msec, u4 nsec);
391 * Get the name of a thread. (For safety, hold the thread list lock.)
393 char* dvmGetThreadName(Thread* thread);
396 * Return true if a thread is on the internal list. If it is, the
397 * thread is part of the GC's root set.
399 bool dvmIsOnThreadList(const Thread* thread);
402 * Get/set the JNIEnv field.
404 INLINE JNIEnv* dvmGetThreadJNIEnv(Thread* self) { return self->jniEnv; }
405 INLINE void dvmSetThreadJNIEnv(Thread* self, JNIEnv* env) { self->jniEnv = env;}
408 * Change the scheduler group of the current process
410 int dvmChangeThreadSchedulerGroup(const char *group);
413 * Update the priority value of the underlying pthread.
415 void dvmChangeThreadPriority(Thread* thread, int newPriority);
419 * Debug: dump information about a single thread.
421 void dvmDumpThread(Thread* thread, bool isRunning);
422 void dvmDumpThreadEx(const DebugOutputTarget* target, Thread* thread,
426 * Debug: dump information about all threads.
428 void dvmDumpAllThreads(bool grabLock);
429 void dvmDumpAllThreadsEx(const DebugOutputTarget* target, bool grabLock);
432 #ifdef WITH_MONITOR_TRACKING
434 * Track locks held by the current thread, along with the stack trace at
435 * the point the lock was acquired.
437 * At any given time the number of locks held across the VM should be
438 * fairly small, so there's no reason not to generate and store the entire
441 typedef struct LockedObjectData {
442 /* the locked object */
445 /* number of times it has been locked recursively (zero-based ref count) */
448 /* stack trace at point of initial acquire */
452 struct LockedObjectData* next;
456 * Add/remove/find objects from the thread's monitor list.
458 void dvmAddToMonitorList(Thread* self, Object* obj, bool withTrace);
459 void dvmRemoveFromMonitorList(Thread* self, Object* obj);
460 LockedObjectData* dvmFindInMonitorList(const Thread* self, const Object* obj);
463 #endif /*_DALVIK_THREAD*/